1. Department of Endocrinology and Metabolism, Peking University People's Hospital , Beijing 100044 , PR China
2. School of Automation, Beijing Institute of Technology , Beijing 100081 , PR China
3. Research Center of Clinical Epidemiology, Peking University Third Hospital , Beijing 100083 , PR China
4. Department of Endocrinology and Metabolism, Affiliated Hospital of Yangzhou University , Yangzhou, Jiangsu 225000 , PR China